1. Field of the Invention
The field relates generally to media input feed systems for an image forming device (“IFD”) having a removable input tray, and, more particularly, to systems and methods for adjusting a pick height of a pick mechanism based on media type.
2. Description of the Related Art
IFDs, such as printers, scanners and photocopiers utilize media feed mechanisms for feeding various types of media sheets into the IFDs. Examples of the various types of media sheets include, but are not limited to, printing paper, bond paper, coated paper, fabrics, transparencies and labels. Almost all of the media feed mechanisms include a pick roller that feeds a media sheet into the IFD for further processing. In a media feed mechanism, various arrangements of the pick roller may exist for feeding the media sheet into the IFD.
Prior pick mechanisms were designed to swing down into the media tray and onto the media stack, and an elevator is used to lift the media stack up to the pick mechanism to raise the pick mechanism and adjust the pick height. The angle at which the pick mechanism contacts the media stack typically provides a corresponding normal force which is applied substantially perpendicular to the flat surface of the media sheet by the pick roller. The pick mechanism also includes a flag that is used in conjunction with a sensor to determine whether or not the pick mechanism is at a standard pick height. Typically, the flag actuates the sensor at a specific pick height location to indicate that the pick mechanism is at the standard pick height. This arrangement, however, has only one available pick height for all types of the media sheets.
As is known, media may have different densities, weights, thicknesses and stiffnesses such that the normal force required to feed one type of media into the IFD may need to be different from the normal force required to feed another type of media in order to avoid multiple feeds or misfeeds. For example, normal media, such as copy paper or bond paper, may be reliably fed by the pick mechanism at the standard pick height, but compressible media, such as envelopes or labels having RFID tags, may compress when picked at the same pick height and drop below the desired pick location due to the pick load from the pick mechanism. Further, the compression could push the compressible media down to pick against a vertical portion of a media dam or separator bracket which could cause a failure to feed. In another example, when heavier or stiffer media, such as cardstock, are picked at the same standard pick height, the leading edge of the heavier media strikes the separator system at a different angle than normal media and can tend to push out the media tray due to the separator system force applied to the stiffer media at that angle. Thus, having only one available pick height for all types of media sheets can result in difficulty with feeding certain media types, and in some cases cause failure to feed.
Accordingly, there is a need for an improved media feed system that can work reliably with different types of media.